Device for supplying power to an electronic computer in a motor vehicle

• US 5,083,078 A
• Filed: 04/25/1991
• Issued: 01/21/1992
• Est. Priority Date: 05/12/1990
• Status: Expired due to Fees

• Current Assignee: Daimler-Benz AG (Mercedes-Benz Group AG)
• Original Assignee: Daimler-Benz AG (Mercedes-Benz Group AG)
• Inventors: Kubler, Freidrich, Kubler, Helmut
• Primary Examiner(s): Wong, Peter S.
• Application Number:
  US07/691,416
• Time in Patent Office: 271 Days
• Field of Search: 323/268, 323/269, 323/272, 323/274, 323/275, 323/276, 323/282, 323/284, 323/285, 323/299, 323/303, 361/18, 340/438, 340/459, 340/461, 340/660, 340/661, 340/662, 340/663
• US Class Current: 323/268
• CPC Class Codes: G05F 1/595 semiconductor devices connected in series
• CPC Class Codes: H02M 1/0045 Converters combining the concepts of switch-mode regulation and linear regulation, e.g. linear pre-regulator to switching converter, linear and switching converter in parallel, same converter or same transistor operating either in linear or switching mode

Abstract

A device for supplying power to an electronic computer in a motor vehicle has first and second voltage regulators, operable independently of one another and having parallel inputs and outputs, and in which a desired output voltage is regulated downwards from an input voltage provided by a vehicle network. The first and second regulators each include at least one capacitive storage element at their inputs. A protective device is coupled to the inputs of the first and second regulators for connecting and disconnecting the first and second regulators from the input voltage. A voltage monitoring circuit is coupled to the first and second regulators and the protective device for detecting and evaluating the input voltage and includes at least one output each for individually controlling activation of the first and second regulators and the protective device. The voltage monitoring circuit includes circuit for controlling, as a function of an evaluation result of the input voltage: no activation of the first and second regulators in an input voltage range from zero up to a first limit; activation of the first regulator in the input voltage range exclusively between the first and a second limit; activation of the second regulator in the input voltage range exclusively between a third and a fourth limit, the third limit being below and the fourth limit above the second limit; and activation of the protective device above the fourth limit for disconnecting the first and second regulators from the input voltage to be regulated downwards.

Claims

1. Device for supplying power to an electronic computer in a motor vehicle, comprising:

first and second voltage regulators, operable independently of one another and having parallel inputs and outputs, and in which a desired output voltage is regulated downwards from an input voltage provided by a vehicle network, the first and second regulators each including at least one capacitive storage means at their inputs;

a protective device coupled to the inputs of the first and second regulators, said protective device including means for connecting and disconnecting the first and second regulators from the input voltage; and

a voltage monitoring circuit coupled to the first and second regulators and the protective device, which said voltage monitoring circuit detects and evaluates the input voltage to be regulated downward from the vehicle network and includes at least one output each for individually controlling activation, voltage range by voltage range, of the first and second regulators and the protective device;

said voltage monitoring circuit including means for controlling, as a function of an evaluation result of the input voltage to be regulated downwards;

no activation of the first and second regulators in an input voltage range from zero up to a first limit;

activation of the first regulator in the input voltage range exclusively between said first and a second limit;

activation of the second regulator in the input voltage range exclusively between a third and a fourth limit, the third limit being below and the fourth limit above the second limit; and

activation of the protective device above the fourth limit for disconnecting said first and second regulators from the input voltage to be regulated downwards.

2. The device according to claim 1, wherein the first regulator is a linear regulator and the second regulator is a switched-mode regulator.

3. The device according to claim 1, wherein for a nominal vehicle network voltage of 14 volts and an output voltage, to be regulated downwards of 5 volts, the first limit is 5.5 volts, the second limit is 10 volts, the third limit is 9.5 volts, and the fourth limit is above 30 volts.

4. The device according to claim 1, further comprising a filter that suppresses high-frequency interference signals coupled to an input of the protective device and an input of the voltage monitoring circuit.

5. The device according to claim 4, wherein the threshold frequency for detecting and evaluating the input voltage to be regulated downwards in the voltage monitoring circuit is tuned to the threshold frequency of the filter.

6. The device according to claim 1, further comprising an arrangement for status interrogation having inputs coupled to outputs of the voltage monitoring circuit, said arrangement having at least one output at which a signal encoding the respective control state is readable.

7. The device according to claim 1, wherein the voltage monitoring circuit has a further input to which a logic signal is providable for the priority setting of all outputs to respective non-activating levels.

8. The device according to claim 1, wherein the voltage monitoring circuit has a further input to which a logic signal is providable for the simultaneous priority setting of the voltage monitoring circuit outputs that are coupled to the inputs of the first and second regulators to the non-activating level, and the voltage monitoring circuit output that is coupled to the protective device to the activating level.

9. The device according to claim 2, wherein for a nominal vehicle network voltage of 14 volts and an output voltage, to be regulated downwards of 5 volts, the first limit is 5.5 volts, the second limit it is 10 volts, the third limit is 9.5 volts, and the fourth limit is above 30 volts.

10. The device according to claim 2, further comprising a filter that suppresses high-frequency interference signals coupled to an input of the protective device and an input of the voltage monitoring circuit.

11. The device according to claim 2, wherein the threshold frequency for detecting and evaluating the input voltage to be regulated downwards in the voltage monitoring circuit is tuned to the threshold frequency of the filter.

12. The device according to claim 2, further comprising an arrangement for status interrogation having inputs coupled to outputs of the voltage monitoring circuit, said arrangement having at least one output at which a signal encoding the respective control state is readable.

13. The device according to claim 2, wherein the voltage monitoring circuit has a further input to which a logic signal is providable for the priority setting of all outputs to respective non-activating levels.

14. The device according to claim 2, wherein the voltage monitoring circuit has a further input to which a logic signal is providable for the simultaneous priority setting of the voltage monitoring circuit outputs that are coupled to the inputs of the first and second regulators to the non-activating level, and the voltage monitoring circuit output that is coupled to the protective device to the activating level.